The following background information may present examples of specific aspects of the prior art (e.g., without limitation, approaches, facts, or common wisdom) that, while expected to be helpful to further educate the reader as to additional aspects of the prior art, is not to be construed as limiting the present disclosure, or any embodiments thereof, to anything stated or implied therein or inferred thereupon.
Typically, dental implant systems are designed to mimic the natural tooth's ability to tolerate the forces encountered during function and help to maintain the surrounding alveolar bone. However, dental implants fail to effectively mimic the shock absorbing characteristics of the periodontal ligament (PDL) for force distribution inherent in natural teeth. The goal of a dental implant system is to restore the patient to normal function, comfort, aesthetics, speech and health regardless of the current oral condition. Often, the dental implant is a surgically placed component that interfaces with the bone of the jaw or skull to support a prosthesis such as a crown, bridge, denture, facial prosthesis or to act as an orthodontic anchor.
The basis for functional stability of the dental implant is a biologic process called osseointegration where fixtures composed of materials, such as titanium, form an intimate bond to bone. The dental implant fixture is first surgically placed, so that it is likely to osseointegrate, into the surrounding alveolar bone, then a dental prosthetic is added after an appropriate time for osseointegration of the dental implant within the alveolar bone has elapsed.
One of the major factors for dental implant failure is inadequate force distribution. This phenomenon can occur with single or multiple unit implant restorations, leading to mechanical overload of the dental implants. These forces, vertical, horizontal, and angular, can cause micro motion (especially compression) of the dental implant within the alveolar bone housing which can cause microvascular injury to the supporting alveolar bone, resulting in alveolar bone degeneration from avascular necrosis and recession of viable supporting alveolar bone around the dental implant potentially resulting in implant disintegration from the alveolar housing under function as alveolar bone support on the dental implant decreases.
Because the cortical alveolar bone is more dense and rigid with less vascularity than the cancellous alvaleor bone, which is below the cortical alveolar bone, compressive functional forces are more deleterious at the cortical alveolar bone level. Higher functional forces cause microvascular damage and occlusion of vascular structures resulting in decreased blood flow and subsequent loss of viability resulting in alveolar bone recession along the alveolar bone/dental implant interface.
Typically, in the natural dentition, force distribution from occlusal forces is provided by the periodontal ligament. The periodontal ligament (PDL) is a system of biomechanically arranged fibers located between the root of a tooth, from the cementoenamel junction to root apex, and the alveolar bone housing of the tooth. The PDL allows the tooth structures to compress into the alveolar bone approximately 0.1 mm to 0.2 mm, which dissipates forces from the tooth into the alveolar bone. This compression causes a piezoelectric effect which promotes maintenance of the alveolar bone. Therefore, the PDL provides a predictable means of force distribution that allows the natural tooth to tolerate high functional loads and maintain supportive alveolar bone.
The cancellous alveolar bone has a greater pliability than the cortical alveolar bone because of the less dense biological bone composition and greater vascularity at the cancellous alveolar bone level. These aforementioned characteristics allow the cancellous alveolar bone to have tolerance for compressive forces and still maintain viability and structural support.
Other proposals have involved dental implant systems and componentry that attempt to absorb horizontal, vertical, and angular forces applied by the opposing teeth. The problem with these devices is that they do not have the benefit of compressive force dissipation inherent in a periodontal ligament. Dental implants have developing bone adhere to their mechanical threads. This osseointegration provides rigid stability to dental implants which prohibits functional compression into the alveolar bone for significant force distribution. Since osseointegration rigidity limits force distribution at the alveolar bone level, force distribution for an implant supported restoration under function is a property of the mechanically created restoration/abutment unit placed on a dental implant.
Thus, an unaddressed need exists in the industry to address the aforementioned deficiencies and inadequacies. Even though the above cited methods for a dental implant meets some of the needs of the market, a dental implant assembly that utilizes a central mobile element, a compressive coil and a compressive ring to direct occlusal forces internally and inferiorly to distribute the occlusal forces uniformly is still desired.